1. Diamond grooves for dull or damaged blades; finely ground tungsten grooves; precision ground ceramic grooves; suitable for grinding all kinds of tools. 2. The material used in the manual sharpener is ABS plus metal, the main body of the sharpener is made of lightweight solid so it can be easily stabilized and fixed in place. 3. It is more convenient to use, with our sharpening stone, you will make more delicious food for your family, which is more durable than other items. It can be used for a long time. 4. Multipurpose sharpener can be used on most kitchen knives kitchen knives, kitchen knives, fruit knives, chef knives, etc. or any other blade without serrations. 5. Just pull the knife a few times from the proper notch, after a few seconds, even an old dull knife is as good as a new one. Please don't sharpen the knife back and forth.